Wafer treatment for achieving defect-free self-assembled monolayers

ABSTRACT

Methods of depositing a film selectively onto a first material relative to a second material are described. The substrate is pre-cleaned by heating the substrate to a first temperature, cleaning contaminants from the substrate and activating the first surface to promote formation of a self-assembled monolayer (SAM) on the first material. A SAM is formed on the first material by repeated cycles of SAM molecule exposure, heating and reactivation of the first material. A final exposure to the SAM molecules is performed prior to selectively depositing a film on the second material. Apparatus to perform the selective deposition are also described.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/008,495, filed Jun. 14, 2018, which claimspriority to U.S. Provisional Application No. 62/519,834, filed Jun. 14,2017, the entire disclosure of which is hereby incorporated by referenceherein.

FIELD

Embodiments of the disclosure generally relate to methods and apparatusto selectively depositing a film. More particularly, embodiments of thedisclosure are directed to methods and apparatus to pre-treat asubstrate to achieve defect-free self-assembled monolayers in selectivedeposition applications.

BACKGROUND

In recent decades, the semiconductor community has made attempts toimprove integrated circuit (IC) processing by replacing lithographysteps with alternatives that translate to lower cost, reduced processingtime, and smaller feature sizes. Many of these alternatives fall underthe blanket category of “selective deposition.” In general, selectivedeposition refers to a process for which the net deposition rate ishigher on the target substrate material relative to other substratematerials, such that the film thickness is achieved on the targetsubstrate material with negligible deposition on the other substratematerials (where “negligible” is defined by process constraints).

Selective deposition is believed to be an effective technique tosignificantly reduce the cost of the patterning process in semiconductordevice fabrication. Selective deposition helps reduce the complexity ofprocess flow resulting in less process steps and higher throughput.

One general strategy to achieve selective deposition employs the use ofblocking layers. Ideally, this strategy involves (1) formation of ablocking layer on substrate materials on which deposition is to beavoided with negligible impact to the target substrate material, (2)deposition on the target substrate material (where deposition on othersubstrate materials is “blocked” by the blocking layer), and (3) removalof the blocking layer without net adverse effects to the deposited film.

One manner of selective deposition uses self-assembled monolayers (SAMs)to enhance the process or deposition selectivity. One of the keyelements of a SAM selective deposition process is the quality of theSAM. For example, a layer of defect free and well packed SAM isimportant for achieving high quality selective deposition. A SAM defectis any form of nanometer size particles or contaminates generated duringSAM deposition process. These particles or contaminants can eventuallytranslate into a failed circuit and cause device yield loss. Inaddition, the packing quality of SAM molecules determines the blockingefficiency which is related to the deposition selectivity. Accordinglythe application of selective deposition is largely dependent on thequality of the SAM layer.

Therefore, there is a need in the art for apparatus and methods toachieve high quality defect free SAM on dielectric or metal surfaces.

SUMMARY

One or more embodiments of the disclosure are directed to processingmethods comprising providing a substrate with an exposed first materialand an exposed second material. The substrate is exposed to a pre-cleanprocess comprising heating the substrate to a first temperature,cleaning the substrate of contaminants and activating a surface of thefirst material to promote formation of a self-assembled monolayer (SAM)on the exposed first material. A SAM is formed on the exposed firstmaterial at a second temperature by exposing the substrate to aplurality of cycles of a SAM formation process followed by a finalexposure to a SAM molecule. Each cycle of the SAM formation processcomprises exposing the substrate to the SAM molecule followed by heatingthe substrate and reactivation of the surface. A film is selectivelydeposited on the exposed second material.

Additional embodiments of the disclosure are directed to processingmethods comprising: (a) providing a substrate with an exposed firstmaterial and an exposed second material; (b) exposing the substrate to apre-clean process comprising heating the substrate to a firsttemperature, cleaning the substrate of contaminants, and exposing thefirst material to an activating agent comprising water vapor to promoteformation of a self-assembled monolayer (SAM) on the exposed firstmaterial; (c) exposing the substrate to a SAM molecule at a secondtemperature that is less than the first temperature to form a portion ofa SAM on the surface of the first material; (d) heating the substrate toa temperature greater than the second temperature; (e) exposing thesubstrate to an activating agent to reactivate the exposed surface ofthe first material; (f) repeating (c) through (e); (g) providing a finalexposure of the SAM molecule to the substrate to form the SAM; and (h)selectively depositing a film on the exposed second material.

Further embodiments of the disclosure are directed to systems tomanufacture an electronic device. The systems comprise a centraltransfer station, a pre-cleaning chamber, a SAM deposition chamber andat least one processor. The central transfer station comprises a robotto move one or more substrates between chambers connected to the centraltransfer station. The pre-cleaning chamber is connected to the centraltransfer station and comprises one or more of a heater, radical sourceor plasma source. The pre-cleaning chamber is in fluid communicationwith an activating agent. The SAM deposition chamber is connected to thecentral transfer station and comprises a pedestal to hold a substrate.The SAM deposition chamber is in fluid communication with one or morereactive gas sources to provide one or more flows of reactive gases tothe SAM deposition chamber. The at least one processor is coupled to thecentral transfer station, the pre-cleaning chamber or the SAM depositionchamber. The at least one processor has one or more configurations tocontrol the formation of a SAM on a first surface of a substrate. Afirst configuration can control cleaning of a substrate in thepre-cleaning chamber. The cleaning comprises heating the substrate to afirst temperature and exposing the substrate to one or more of a plasmafrom a plasma source or radicals from a radical source. A secondconfiguration can control the flow of the activating agent to thesubstrate. A third configuration can control movement of the substratefrom the pre-cleaning chamber to the SAM deposition chamber through thecentral transfer station using the robot. A fourth configuration canform a SAM comprising multiple cycles of exposure to a SAM molecule,heating the substrate and exposure to an activating agent.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the recited features of the presentdisclosure can be understood in detail, a more particular description ofthe disclosure, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this disclosure and are therefore not to beconsidered limiting of its scope, for the disclosure may admit to otherequally effective embodiments.

FIGS. 1A through 1C show a schematic of an ideal self-assembledmonolayer assisted selective deposition process;

FIGS. 2A through 2C show a schematic of a conventional self-assembledmonolayer assisted selective deposition process;

FIG. 3 illustrates a flowchart of a self-assembled monolayer assistedselective deposition method in accordance with one or more embodiment ofthe disclosure;

FIGS. 4A through 4C show a schematic of a pre-clean process inaccordance with one or more embodiment of the disclosure;

FIGS. 5A through 5H show a schematic representation of a SAM formationprocess in accordance with one or more embodiment of the disclosure;

FIG. 6 shows a schematic of a substrate with a self-assembled monolayerassisted selective deposition in accordance with one or more embodimentof the disclosure;

FIG. 7 shows a schematic of a substrate after removal of the SAM afterselective deposition in accordance with one or more embodiment of thedisclosure;

FIG. 8 is a block diagram of a process chamber in accordance with one ormore embodiment of the disclosure; and

FIG. 9 is a block diagram of a cluster tool system in accordance withone or more embodiment of the disclosure.

DETAILED DESCRIPTION

As used in this specification and the appended claims, the term“substrate” and “wafer” are used interchangeably, both referring to asurface, or portion of a surface, upon which a process acts. It willalso be understood by those skilled in the art that reference to asubstrate can also refer to only a portion of the substrate, unless thecontext clearly indicates otherwise. Additionally, reference todepositing on a substrate can mean both a bare substrate and a substratewith one or more films or features deposited or formed thereon.

A “substrate” as used herein, refers to any substrate or materialsurface formed on a substrate upon which film processing is performedduring a fabrication process. For example, a substrate surface on whichprocessing can be performed include materials such as silicon, siliconoxide, strained silicon, silicon on insulator (SOI), carbon dopedsilicon oxides, silicon nitride, doped silicon, germanium, galliumarsenide, glass, sapphire, and any other materials such as metals, metalnitrides, metal alloys, and other conductive materials, depending on theapplication. Substrates include, without limitation, semiconductorwafers. Substrates may be exposed to a pretreatment process to polish,etch, reduce, oxidize, hydroxylate (or otherwise generate or grafttarget chemical moieties to impart chemical functionality), annealand/or bake the substrate surface. In addition to film processingdirectly on the surface of the substrate itself, in the presentdisclosure, any of the film processing steps disclosed may also beperformed on an underlayer formed on the substrate as disclosed in moredetail below, and the term “substrate surface” is intended to includesuch underlayer as the context indicates. Thus for example, where afilm/layer or partial film/layer has been deposited onto a substratesurface, the exposed surface of the newly deposited film/layer becomesthe substrate surface. What a given substrate surface comprises willdepend on what films are to be deposited, as well as the particularchemistry used. In one or more embodiments, the first substrate surfacemay comprise a metal, metal oxide, or H-terminated Si_(x)Ge_(1-x), andthe second substrate surface may comprise a Si-containing dielectric, orvice versa. In some embodiments, a substrate surface may comprisecertain functionality (e.g., —OH, —NH, etc.).

As used in this specification and the appended claims, the terms“reactive gas”, “precursor”, “reactant”, and the like, are usedinterchangeably to mean a gas that includes a species which is reactivewith a substrate surface. For example, a first “reactive gas” may simplyadsorb onto the surface of a substrate and be available for furtherchemical reaction with a second reactive gas.

Embodiments of the disclosure provide methods of selectively depositinga film onto one surface over a second surface. As used in thisspecification and the appended claims, the term “selectively depositinga film on one surface over another surface”, and the like, means that afirst amount of the film is deposited on the first surface and a secondamount of film is deposited on the second surface, where the secondamount of film is less than the first amount of film, or no film isdeposited on the second surface. The term “over” used in this regarddoes not imply a physical orientation of one surface on top of anothersurface, rather a relationship of the thermodynamic or kineticproperties of the chemical reaction with one surface relative to theother surface. For example, selectively depositing a cobalt film onto acopper surface over a dielectric surface means that the cobalt filmdeposits on the copper surface and less or no cobalt film deposits onthe dielectric surface; or that the formation of the cobalt film on thecopper surface is thermodynamically or kinetically favorable relative tothe formation of a cobalt film on the dielectric surface.

Embodiments of the disclosure incorporate a blocking layer called aself-assembled monolayer (SAM). Fundamentally, SAMs are orderedassemblies formed by the adsorption of an active surfactant on a solidface. These molecules are typically comprised of one or more moietieswith an affinity for the substrate (head group) and a relatively long,inert, linear hydrocarbon moiety (tail group). Due to surface propertydifference, the adsorption of SAM is heavily dependent on the materialof the substrate, i.e., the deposition of SAM is selective. Withoutbeing bound by any particular theory of operation, it is believed thatSAM formation happens through fast adsorption of molecular head groupsat the substrate surface and slow association of molecular tail groupswith each other through van der Waals interactions. SAM precursors arechosen such that the head group selectively reacts with the substratematerials to be blocked during deposition.

Following the SAM growth, deposition of a film can be performed. Thelong carbon chain of SAM blocks the growth of the film. As aconsequence, the film grows substantially only in the area not coveredby SAM achieving selective film deposition. The SAMs can be removedthrough thermal decomposition (with desorption of any byproducts) or anintegration-compatible ashing process.

An idealized traditional process flow of selective deposition is shownin the FIGS. 1A through 1C. A patterned substrate includes a firstmaterial 10 and a second material 20. In FIG. 1B, a SAM 30 is grown bychemical vapor deposition (CVD) on the first material 10. In FIG. 1C, athird material 40 is deposited on the second material 20 by atomic layerdeposition (ALD). The SAM 30 is used as a sacrificial layer to enableselective deposition of the third material 40 on the second material 20without little or no deposition on the first material 10.

As the enabler for selective deposition, the quality of the SAM 30 layeris determinative of selectivity. There are two major issues that candegrade the SAM quality and deposition selectivity. As shown in FIG. 2A,nanometer size particles 25 can be generated on the second material 20during SAM 30 growth on the first material 10 and packing defects 15 canbe formed in the SAM 30. Additionally, particles 25 can be formed on thesecond material 20 during the formation of the SAM 30. As illustrated inFIG. 2B, the ALD growth is prevented by the SAMs but growth 45 can occurinside the SAM packing defect 15 area. The packing defects 15 create anissue with the SAM blocking ability on the first material 10.Additionally, the particles 25 can interfere with deposition of thethird material 40 on the second material 20. FIG. 2C shows the growth 45where there were SAM defects after removing the sacrificial SAM layer.These defects (i.e., growth on the first material 10 and particles 25 onthe second material 20) can result in either an electrical short orbreak in the circuit, leading to a loss in yield of the device.

Accordingly, one or more embodiments of the disclosure provide processesto form SAM blocking layers without or with reduced defects. Someembodiments provide methods to deposit SAM blocking layers that reducethe particulate formation on the surfaces not being blocked. Someembodiments provide apparatus to perform a process to form a SAMblocking layer and deposit a material on unblocked surfaces.

In general, embodiments of the method include a wafer surface plasmatreatment before SAM deposition and splitting of the SAM depositionprocess into multiple shorter phases. In-between some or each SAMdeposition phase, a thermal treatment process can be added prior to theSAM deposition. In some embodiments, the plasma treatment processincludes introduction of hydrogen radicals to remove the wafer surfaceabsorbed organic contaminates and water vapor remote plasma source toactivate the surface for SAM deposition. During the plasma treatmentprocess, the wafer temperature and concentration of chemicals arecontrolled. In some embodiments, the SAM deposition is broken into shortexposures. An interim thermal treatment can be used to remove lowquality SAMs. The number of deposition/treatment cycles can bedetermined by the blocking requirement. Generally, more cycles willresult in increased blocking performance with a gradual decrease in theincremental improvements between cycles as the surface blocking becomessaturated.

According to some embodiments, selective deposition of a film is enabledthrough the use of self-assembled monolayers (SAMs) to block deposition.Flaw or defects in the SAMs can cause failed circuits and device yieldloss. In some embodiments, the wafer (or substrate) is pretreated toclean contaminants and heat the wafer to a temperature higher than asubsequent SAM step. The pre-clean process of some embodiments finisheswith a surface treatment to replenish the hydroxyl terminations on thesurface.

After pre-clean, the wafer can be moved to a SAM deposition chamber thathas a process temperature lower than the temperature of the wafer duringcleaning and transfer to the SAM deposition chamber. The highertemperature wafer, relative to the SAM deposition chamber, can helpprevent condensation and surface contamination by particulate formation.

In some embodiments, the SAM formation process is a repeating pattern ofSAM reactant exposure, exposure to a hydroxylating process and thermaltreatment. The SAM formation process can be repeated any number of timesto form a suitable SAM. The SAM formation process of some embodimentsends with a SAM exposure without subsequent heating or hydroxylation.

In some embodiments, when the wafer is moved into the SAM depositionchamber, the wafer is remains hotter than the conditions in the SAMdeposition chamber. The wafer will equilibrate to the temperature of thepedestal in the SAM deposition chamber to be at the process temperature.Each cycle can reheat the wafer to a temperature greater than or equalto the SAM deposition chamber to prevent condensation and particulateformation.

In some embodiments, after SAM formation is complete, the wafer is moveddirectly to a processing chamber for formation of the film on thenon-SAM containing surface. In one or more embodiments, the SAM isformed on a dielectric surface and the subsequent deposition is on ametal surface.

In some embodiments, the selectivity of the deposition process isimproved by forming a more uniform SAM on the first surface and byreducing surface defects (particulates) on the second surface. In someembodiments, selective deposition is improved through the use ofmultiple SAM deposition processes with thermal treatments and surfaceactivation (e.g., hydroxylation) in between.

FIG. 3 provides a flowchart of an exemplary method 100 in accordancewith one or more embodiment of the disclosure. FIGS. 4A through 4Cillustrate a substrate with an exposed first material 10 and an exposedsecond material 20 going through the pre-clean process 120. An exposedsurface, as used herein, refers to a surface that is available forsurface reaction (i.e., not hindered by intervening molecules orchemistry (e.g., native oxides)). FIGS. 5A through 5H illustrate thesubstrate during SAM formation and FIG. 6 illustrates the substrateafter deposition of the film 40. The substrates illustrated in FIGS. 4Athrough 6 show one first material 10 and one second material 20. Thoseskilled in the art will understand that this is merely for descriptivepurposes and that a substrate can have more than one first material 10and more than one second material 20.

In method 100, at stage 110, a substrate is provided for processing. Asused in this manner, the term “provided” means that the substrate isplaced into position for processing. The substrate and individualsurfaces can be formed in-situ or can be formed ex-situ and moved intothe process chamber or environment.

The substrate includes a first material 10 and a second material 20.Both the first material 10 and the second material 20 have exposedsurfaces upon which a deposition or SAM formation can occur. The firstmaterial 10 of some embodiments comprises a dielectric. In someembodiments, the second material 20 comprises a metal or conductivematerial.

The pre-clean process 120 is illustrated in FIGS. 4A through 4C. In thepre-clean process 120, the substrate with the first material 10 and thesecond material 20 is heated. The substrate can be heated by anysuitable heating components including, but not limited to, lamps,resistive heating or inductive heating. The pre-clean process 120 ofsome embodiments removes impurities, contaminants and defects on thesubstrate that might serve as a nucleation site. FIG. 4A illustrates asubstrate with a first material 10 and a second material 20. Both thefirst material 10 and second material 20 are shown with particulates 50on the surfaces.

FIG. 4B illustrate the substrate after heater where the first material10 and the second material 20 have been cleaned of particulates 50.Deactivated areas 12 of the first material 10 are shown. Thesedeactivated areas 12 can be present before heating or can arise as aresult of the heating process. The deactivated areas 12 are any areathat has a surface termination that is not favorable for the formationof a self-assembled monolayer. The substrate is exposed to an activatingagent to remove the deactivated areas 12, as shown in FIG. 4C.

The activating agent can be any suitable compound that can convert thesurface terminations to a termination that is favorable for SAMformation. In some embodiments, the first material 10 has a hydroxylterminated surface and the deactivated areas 12 are not hydroxylterminated. For example, the cleaning process can cause some of thesurface hydroxyl groups to be removed. Exposure to the activating agentcan replenish the hydroxyl groups so that an amino-substituted silanecan form a closely packed self-assembled monolayer. The activating agentexposure and heating can occur sequentially or at the same time. In someembodiments, the substrate is heated and cleaned prior to exposure tothe activating agent.

In some embodiments, the pre-clean process 120 occurs in a pre-cleanchamber. The pre-clean chamber of some embodiments includes one or moreof a remote plasma source (RPS), a radical source, pedestal or a heater.

The cleaning process of some embodiments includes exposing the substrateto one or more of a plasma or radicals. In some embodiments, thesubstrate is exposed to a plasma comprising one or more of He, Ar, Ne,Kr, H₂, N₂, H₂O, air, O₂, NO or NO₂. In some embodiments, the substrateis exposed to radicals generated in a remote plasma source using one ormore of the plasma gases. In some embodiments, the substrate is exposedto radicals generated by passing one or more of He, Ar, Ne, Kr, H₂, N₂,H₂O, air, O₂, NO or NO₂ across a hot wire.

In some embodiments, the activating agent comprises water vapor. Thewater vapor can be exposed to the substrate and the first material 10 bybeing co-flowed into the processing chamber or pre-clean chamber in acarrier gas. In some embodiments, the activating agent is co-flowed witha carrier gas, diluent gas and/or inert gas. In one or more embodiments,the activating agent comprises water vapor generated in a remote plasmasource and flowed in a pre-clean chamber to activate the substratesurface.

During the pre-clean process 120, the substrate is heated to a firsttemperature. The first temperature can be any suitable temperature thatis greater than or equal to the deposition temperature to be used in theSAM formation process that will follow. In some embodiments, the firsttemperature is in the range of about 200° C. to about 350° C. In someembodiments, the first temperature is greater than a SAM depositiontemperature by greater than or equal to about 10° C., 15° C., 20° C.,25° C., 50° C., 75° C. or 100° C.

The pressure in the pre-clean chamber can be in the range of about 1 toabout 100 Torr. The substrate can be exposed to the pre-clean processfor a time up to or equal to about 5 minutes, 4 minutes, 3 minutes, 2minutes, 90 seconds, 60 seconds, 45 seconds or 30 seconds.

After cleaning the substrate, a self-assembled monolayer can be formedon the first material 10. In some embodiments, the substrate is moved130 from a pre-clean chamber to a SAM deposition chamber for formationof the SAM. In some embodiments, the SAM is formed in the same chamberas the pre-clean.

In the SAM deposition chamber, the substrate is exposed to a SAMformation process. The SAM can be formed on the exposed first material10 at a second temperature by exposing the substrate to a plurality ofcycles of a SAM formation process followed by a final exposure to a SAMmolecule. Each cycle of the SAM formation process comprises a SAMmolecule exposure 140 (see FIG. 3).

The second temperature is less than or equal to about the firsttemperature so that the substrate is heated in the pre-clean chamber toa temperature that is higher than the temperature in the SAM depositionchamber. The substrate at the higher temperature can be moved to the SAMdeposition chamber at a lower temperature and positioned on thesubstrate support. In the substrate support, the substrate can rapidlyequilibrate to the temperature of the substrate support (i.e., thetemperature of the SAM deposition chamber or process). With a substratetemperature greater than the temperature of the SAM deposition chamberthere is a reduced risk or chance that condensation of particulates orcontaminants will occur on the substrate surface so that subsequent SAMformation or deposition is not affected. In some embodiments, the secondtemperature is in the range of about 100° C. to about 200° C., or in therange of about 125° C. to about 175° C., or about 150° C. In someembodiments, the second temperature is less than the first temperatureby an amount greater than or equal to about 10° C., 15° C., 20° C., 25°C., 50° C., 75° C. or 100° C.

Referring to FIG. 5A through 5H, the SAM 30 can be formed by multipleexposures to a SAM molecule 31. The SAM molecule can be any suitablemolecule that can form a self-assembled monolayer on the first surface10. In some embodiments, the SAM molecule comprises an amino-substitutedsilane with a non-polar tail. In some embodiments, the non-polar tailcomprises an alkyl chain with greater than or equal to about 6 carbonatoms. In one or more embodiments, the SAM molecule comprises anamino-substituted silane with an 18 carbon chain tail.

Typically, formation of a self-assembled monolayer occurs over a periodof time until approximately steady-state monolayer formation occurs. Theamount of time that the substrate is exposed to the SAM molecules isless than the amount of time that would be employed to reachsteady-state monolayer. In some embodiments, the amount of time that thesubstrate is exposed to the SAM molecule is in the range of about 10% toabout 90% of the amount of time to reach steady-state. In someembodiments, the amount of time that the substrate is exposed to the SAMmolecule is less than or equal to about 80%, 70%, 60%, 50%, 40%, 30%,20% or 10% of the time to reach steady state. In some embodiments, theSAM molecule is exposed to the first material 10 for a time less than orequal to about 10 minutes, 9 minutes, 8 minutes, 7 minutes, 6 minutes, 5minutes, 4 minutes, 3 minutes, 2 minutes, 1 minute, 45 seconds, 30seconds, 25 seconds, 20 seconds or 15 seconds, for each cycle.

Referring to FIG. 5B, a first amount of SAM molecules are adsorbed ontothe first material 10. In some embodiments, the first amount of SAMmolecules is in the range of about 10% to about 90% of a monolayer, orin the range of about 20% to about 80% of a monolayer, or in the rangeof about 30% to about 70% of a monolayer. In some embodiments, the firstamount of SAM molecules adsorbed is less than or equal to about 80%,70%, 60%, 50%, 40%, 30%, 20% or 10% of a monolayer.

The SAM molecules can be well-packed or dispersed across the firstmaterial 10. In the embodiment illustrated in FIG. 5B, the SAM moleculesare dispersed about the surface and are not well-packed. Additionally,the exposure to the SAM molecules can form deactivated areas 12 on thefirst material 10. As used in manner, the term “well-packed” means thatthe spacing between SAM molecules 31 or the density of SAM molecules 31per unit area are greater than or equal to 60%, 70%, 80% or 90% of thetheoretical spacing or density for the monolayer.

After exposure to the SAM molecules, the method 100 reaches decision150. If additional cycles of SAM molecule exposure are to follow, themethod moves to heating 160. The substrate with the first material 10with the partial monolayer of SAM molecules 31 is subjected to a heatingprocess. The heating process elevates the temperature of the substrateto a third temperature that is greater than the second temperature. TheSAM molecules 31 on the first material 10 surface can rearrange and formwell-packed regions 32 of SAM molecules 31, as shown in FIG. 5C.

After heating 160, the first material 10 can be subjected to activation170. Activation 170 comprises exposing the substrate to an activatingagent to reactivate the deactivated areas 12, as shown in FIG. 5D.

The heating 160 and activation 170 can be performed in the same chamberas the SAM molecule exposure or in a different chamber. In someembodiments, the substrate is moved from the SAM deposition chamber tothe pre-clean chamber for heating 160 and activation 170 and then movedback to the SAM deposition chamber for subsequent SAM molecule exposure140.

The method 100 repeats the SAM molecule exposure 140. As shown in FIG.5E, additional SAM molecules 31 are adsorbed onto the first material 10.The additional SAM molecules 31 can be dispersed across the surface sothat there are regions of well-packed molecules and regions ofloosely-packed molecules. Addition regions of the first material 10surface can also become deactivated. FIG. 5F shows the result of heating160 the substrate to form well-packed regions 32 of SAM molecules andFIG. 5G illustrates the effect of activation 170 of the first material10 to remove any deactivated areas 12.

The cycle of SAM molecule exposure 140, heating 160 and activation 170can be repeated, assuming that decision 150 follows the ‘no’ path shownin FIG. 3. The cycle repeats until the decision point 150 has a positiveresult that will stop the cycle from proceeding to the heating andactivation stages. FIG. 5H shows a substrate with a first material 10and a second material 20 with a well-packed SAM 30 on the first material10. There are little or no particulates 50 or diffusely packed areas ofthe SAM

As shown in FIG. 6, after formation of the well-packed SAM 30, thesubstrate can be subjected to a selective deposition process where afilm 40 is deposited on the second material 20 and substantially no filmis deposited on the first material 10. As used in this manner, the term“substantially no film” means that the surface has less than or equal toabout 5%, 4%, 3%, 2% or 1% area that has the film 40 deposited thereon.

In some embodiments, the film 40 is deposited 190 on the second material20 in a different process chamber than the SAM deposition chamber. Themethod 100 might include moving the substrate from the SAM depositionchamber 180 after the final exposure to the SAM molecule to a selectivedeposition chamber. The selective deposition chamber can be any suitabledeposition chamber including, but not limited to, a chemical vapordeposition (CVD) chamber, an atomic layer deposition (ALD) chamber, aplasma-enhanced chemical vapor deposition (PECVD) chamber, a plasmaenhanced atomic layer deposition (PEALD) chamber, or a physical vapordeposition (PVD) chamber.

The film 40 can be any suitable material depending on the process beingimplemented. In some embodiments, the film 40 is deposited to the secondmaterial 20 as a hafnium oxide film. In some embodiments, the film 40 isa dielectric material. In some embodiments, the film 40 is a high-kdielectric (k>5). In some embodiments, the film 40 is a low-k dielectric(k<=5).

After deposition of the film 40, the SAM can be left on the firstmaterial 10 or removed. In some embodiments, the SAM is removed from thefirst material 10 after deposition of the film 40, as shown in FIG. 7.Removing the SAM can be accomplished by any suitable method dependingon, for example, the SAM molecule used or the thermal budget of thedevice being formed. In some embodiments, removing the SAM comprises oneor more of a plasma ash process or thermal desorption.

FIG. 8 shows a block diagram of a plasma system 800 to perform at leastsome of the operations to pre-clean, form a SAM and/or the selectivedeposition process. The system 1800 illustrated has a processing chamber801. A movable pedestal 802 to hold a substrate 803 that has beenpositioned in processing chamber 801. Pedestal 802 can comprise anelectrostatic chuck (“ESC”), a DC electrode embedded into the ESC, and acooling/heating base. In an embodiment, pedestal 802 acts as a movingcathode. In an embodiment, the ESC comprises an Al₂O₃ material, Y₂O₃, orother ceramic materials known to one of ordinary skill of electronicdevice manufacturing. A DC power supply 804 can be connected to the DCelectrode of the pedestal 802. In some embodiments, the pedestal 801includes a heater (not shown) that is capable of raising the temperatureof the substrate to the first temperature. While an electrostatic chuckis illustrated as the pedestal 802, those skilled in the art willunderstand that this is merely exemplary and other pedestal types arewithin the scope of the disclosure.

As shown in FIG. 8, a substrate 803 can be loaded through an opening 808and placed on the pedestal 802. System 800 comprises an inlet to inputone or more process gases 812 through a mass flow controller 811 to aplasma source 813. A plasma source 813 comprising a showerhead 814 iscoupled to the processing chamber 801 to receive one or more gases 812to generate plasma. Plasma source 813 is coupled to a RF source power810. Plasma source 813 through showerhead 814 generates a plasma 815 inprocessing chamber 801 from one or more process gases 812 using a highfrequency electric field. Plasma 815 comprises plasma particles, such asions, electrons, radicals or any combination thereof. In an embodiment,power source 810 supplies power from about 50 W to about 3000 W at afrequency from about 400 kHz to about 162 MHz to generate plasma 815.

A plasma bias power 805 is coupled Io the pedestal 802 (e.g., cathode)via a RF match 807 to energize the plasma. In an embodiment, the plasmabias power 805 provides a bias power that is not greater than 1000 W ata frequency between about 2 MHz to 60 MHz, and in a particularembodiment at about 13 MHz. A plasma bias power 806 may also beprovided, for example, to provide another bias power that is not greaterthan 1000 W at a frequency from about 400 kHz to about 60 MHz, and in aparticular embodiment, at about 60 MHz. Plasma bias power 806 and biaspower 805 are connected Io RF match 807 to provide a dual frequency biaspower. In an embodiment, a total bias power applied to the pedestal 802is from about 10 W to about 3000 W.

As shown in FIG. 8, a pressure control system 809 provides a pressure toprocessing chamber 801. The chamber 801 has one or more exhaust outlets816 to evacuate volatile products produced during processing in thechamber. In an embodiment, the plasma system 800 is an inductivelycoupled plasma (ICP) system. In an embodiment, the plasma system 800 isa capacitively coupled plasma (CCP) system.

In some embodiments, a control system 817 is coupled to the chamber 801.The control system 817 comprises a processor 818, a temperaturecontroller 819 coupled to the processor 818, a memory 820 coupled to theprocessor 818, and input/output devices 821 coupled to the processor818. The memory 820 can include one or more of transitory memory (e.g.,random access memory) and non-transitory memory (e.g., storage).

In one embodiment, the processor 818 has a configuration to control oneor more of: the formation of a SAM on a first surface of a substrate;cleaning of a substrate in the pre-cleaning chamber, the cleaningcomprising heating the substrate to a first temperature and exposing thesubstrate to one or more of a plasma from a plasma source or radicalsfrom a radical source; the flow of the activating agent to thesubstrate; forming a SAM comprising multiple cycles of exposure to a SAMmolecule, heating the substrate and exposure to an activating agent.

The control system 817 can be configured to perform at least some of themethods as described herein and may be either software or hardware or acombination of both. The plasma system 800 may be any type of highperformance processing plasma systems known in the art, such as but notlimited to an etcher, a cleaner, a furnace, or any other plasma systemto manufacture electronic devices.

FIG. 9 illustrates a system 900 that can be used to process a substrateaccording to one or more embodiment of the disclosure. The system 900can be referred to as a cluster tool. The system 900 includes a centraltransfer station 910 with a robot 912 therein. The robot 912 isillustrated as a single blade robot; however, those skilled in the artwill recognize that other robot 912 configurations are within the scopeof the disclosure. The robot 912 is configured to move one or moresubstrate between chambers connected to the central transfer station910.

At least one pre-clean chamber 920 is connected to the central transferstation 910. The pre-clean chamber 920 can include one or more of aheater, a radical source or plasma source. The pre-clean chamber 920 isin fluid communication with an activating agent. An exemplary pre-cleanchamber 920 is illustrated in FIG. 8 as a plasma system 800.

In some embodiments, there are two pre-clean chambers 920 connected tothe central transfer station 910. In the embodiment shown in FIG. 9, thepre-clean chambers 920 can act as pass through chambers between thefactory interface 905 and the central transfer station 910. The factoryinterface 905 can include one or more robot 906 to move substrate from acassette to the pre-clean chamber 920. The robot 912 can them move thesubstrate from the pre-clean chamber 920 to other chambers within thesystem 900.

A SAM deposition 930 chamber can be connected to the central transferstation 910. The SAM deposition chamber 930 comprising a pedestal tohold a substrate. The SAM deposition chamber 930 is in fluidcommunication with one or more reactive gas sources to provide one ormore flows of reactive gases to the SAM deposition chamber 930. Thereactive gases of the SAM deposition chamber include the SAM moleculethat can for the monolayer on the substrate.

The SAM deposition chamber 930 can be any suitable chamber that canprovide a flow of SAM molecules and control the temperature of thesubstrate. The plasma system 800 shown in FIG. 8 can also be used as theSAM deposition chamber 930. The substrate can be moved to and from theSAM deposition chamber 930 by the robot 912 passing through isolationvalve 914.

A selective deposition chamber 940 can also be connected to the centraltransfer station 910. The selective deposition chamber 940 can be anysuitable deposition chamber including, but not limited to, CVD, ALD,PECVD, PEALD or PVD chambers. In some embodiments, the selectivedeposition chamber 940 comprises an ALD chamber. The ALD chamber can bea time-domain chamber where the reactive gases are sequentially exposedto the substrate so that only one reactive gas is present in the chamberat any given time. In some embodiments, the ALD chamber is a spatial ALDchamber with the reactive gases are flowed into separate regions of theprocessing chamber at the same time and the reactive gases are separatedby a gas curtain to prevent gas phase reactions between the reactivegases. In a spatial ALD chamber, the substrate is moved between regionsof the processing chamber containing the various reactive gases todeposit a film.

Other process chambers can be connected to the central transfer station910. In the embodiment shown, an ashing chamber 960 is connected to thecentral transfer station 910 through isolation valve 914. The ashingchamber 960 can be any suitable chamber that can remove the SAM afterselective deposition.

At least one controller 950 is coupled to the central transfer station910, the pre-clean chamber 920, the SAM deposition chamber 930, theselective deposition chamber 940 or the ashing chamber 960. In someembodiments, there are more than one controller 950 connected to theindividual chambers or stations and a primary control processor iscoupled to each of the separate processors to control the system 900.The controller 950 may be one of any form of general-purpose computerprocessor, microcontroller, microprocessor, etc., that can be used in anindustrial setting for controlling various chambers and sub-processors.

The at least one controller 950 can have a processor 952, a memory 954coupled to the processor 952, input/output devices 956 coupled to theprocessor 952 and circuits 958 to communication between the differentelectronic components. The memory 954 can include one or more oftransitory memory (e.g., random access memory) and non-transitory memory(e.g., storage).

The memory 954, or computer-readable medium, of the processor may be oneor more of readily available memory such as random access memory (RAM),read-only memory (ROM), floppy disk, hard disk, or any other form ofdigital storage, local or remote. The memory 954 can retain aninstruction set that is operable by the processor 952 to controlparameters and components of the system 900. The support circuits 958are coupled to the processor 952 for supporting the processor in aconventional manner. Circuits may include, for example, cache, powersupplies, clock circuits, input/output circuitry, subsystems, and thelike.

Processes may generally be stored in the memory as a software routinethat, when executed by the processor, causes the process chamber toperform processes of the present disclosure. The software routine mayalso be stored and/or executed by a second processor (not shown) that isremotely located from the hardware being controlled by the processor.Some or all of the method of the present disclosure may also beperformed in hardware. As such, the process may be implemented insoftware and executed using a computer system, in hardware as, e.g., anapplication specific integrated circuit or other type of hardwareimplementation, or as a combination of software and hardware. Thesoftware routine, when executed by the processor, transforms the generalpurpose computer into a specific purpose computer (controller) thatcontrols the chamber operation such that the processes are performed.

In some embodiments, the controller 950 is configured to form a SAM on afirst surface of a substrate. The controller 950 can have variousconfigurations and each configuration can be stored separately in thememory 954 or in separate memories. A first configuration can controlcleaning of a substrate in the pre-clean chamber 920. The firstconfiguration may include instructions to heat the substrate to a firsttemperature and/or instructions to expose the substrate to one or moreof a plasma from a plasma source or radicals from a radical source. Asecond configuration can control the flow of the activating agent to thesubstrate. A third configuration can control movement of the substratefrom the pre-clean chamber 920 to the SAM deposition chamber 930 throughthe central transfer station 910 using the robot 912. A fourthconfiguration can form a SAM. The fourth configuration may includeinstructions to perform multiple cycles of exposure to a SAM molecule,heating the substrate and exposure to an activating agent. The fourthconfiguration may also include instructions to move the substratebetween the SAM deposition chamber 930 and the pre-clean chamber 920 forthe different exposure. A fifth configuration may include instructionsto selectively deposit a film on the substrate in the selectivedeposition chamber 940. The fifth configuration may include instructionsets to move the substrate to the deposition chamber 940, heat thesubstrate in the chamber, provide a flow of gas to the chamber and/orremove the substrate after deposition. A sixth configuration may includeinstructions to remove the SAM from the substrate surface. The sixthconfiguration may include instructions to move the substrate to theashing chamber 960 and providing gas flows and temperatures to removethe SAM. The controller can operate valves, actuators, motors, etc., toimplement any of the configurations or processes as needed.

According to one or more embodiments, the substrate is subjected toprocessing prior to and/or after forming the layer. This processing canbe performed in the same chamber or in one or more separate processingchambers. In some embodiments, the substrate is moved from the firstchamber to a separate, second chamber for further processing. Thesubstrate can be moved directly from the first chamber to the separateprocessing chamber, or it can be moved from the first chamber to one ormore transfer chambers, and then moved to the separate processingchamber. Accordingly, the processing apparatus may comprise multiplechambers in communication with a transfer station. An apparatus of thissort may be referred to as a “cluster tool” or “clustered system,” andthe like.

Generally, a cluster tool is a modular system comprising multiplechambers which perform various functions including substratecenter-finding and orientation, degassing, annealing, deposition and/oretching. According to one or more embodiments, a cluster tool includesat least a first chamber and a central transfer chamber. The centraltransfer chamber may house a robot that can shuttle substrates betweenand among processing chambers and load lock chambers. The transferchamber is typically maintained at a vacuum condition and provides anintermediate stage for shuttling substrates from one chamber to anotherand/or to a load lock chamber positioned at a front end of the clustertool. Two well-known cluster tools which may be adapted for the presentinvention are the Centura® and the Endura®, both available from AppliedMaterials, Inc., of Santa Clara, Calif. However, the exact arrangementand combination of chambers may be altered for purposes of performingspecific steps of a process as described herein. Other processingchambers which may be used include, but are not limited to, cyclicallayer deposition (CLD), atomic layer deposition (ALD), chemical vapordeposition (CVD), physical vapor deposition (PVD), etch, pre-clean,chemical clean, thermal treatment such as RTP, plasma nitridation,degas, orientation, hydroxylation and other substrate processes. Bycarrying out processes in a chamber on a cluster tool, surfacecontamination of the substrate with atmospheric impurities can beavoided without oxidation prior to depositing a subsequent film.

According to one or more embodiments, the substrate is continuouslyunder vacuum or “load lock” conditions, and is not exposed to ambientair when being moved from one chamber to the next. The transfer chambersare thus under vacuum and are “pumped down” under vacuum pressure. Inertgases may be present in the processing chambers or the transferchambers. In some embodiments, an inert gas is used as a purge gas toremove some or all of the reactants. According to one or moreembodiments, a purge gas is injected at the exit of the depositionchamber to prevent reactants from moving from the deposition chamber tothe transfer chamber and/or additional processing chamber. Thus, theflow of inert gas forms a curtain at the exit of the chamber.

The substrate can be processed in single substrate deposition chambers,where a single substrate is loaded, processed and unloaded beforeanother substrate is processed. The substrate can also be processed in acontinuous manner, similar to a conveyer system, in which multiplesubstrate are individually loaded into a first part of the chamber, movethrough the chamber and are unloaded from a second part of the chamber.The shape of the chamber and associated conveyer system can form astraight path or curved path. Additionally, the processing chamber maybe a carousel in which multiple substrates are moved about a centralaxis and are exposed to deposition, etch, annealing, cleaning, etc.processes throughout the carousel path.

During processing, the substrate can be heated or cooled. Such heatingor cooling can be accomplished by any suitable means including, but notlimited to, changing the temperature of the substrate support andflowing heated or cooled gases to the substrate surface. In someembodiments, the substrate support includes a heater/cooler which can becontrolled to change the substrate temperature conductively. In one ormore embodiments, the gases (either reactive gases or inert gases) beingemployed are heated or cooled to locally change the substratetemperature. In some embodiments, a heater/cooler is positioned withinthe chamber adjacent the substrate surface to convectively change thesubstrate temperature.

The substrate can also be stationary or rotated during processing. Arotating substrate can be rotated continuously or in discrete steps. Forexample, a substrate may be rotated throughout the entire process, orthe substrate can be rotated by a small amount between exposures todifferent reactive or purge gases. Rotating the substrate duringprocessing (either continuously or in steps) may help produce a moreuniform deposition or etch by minimizing the effect of, for example,local variability in gas flow geometries.

Reference throughout this specification to “some embodiments,” “certainembodiments,” “one or more embodiments” or “an embodiment” means that aparticular feature, structure, material, or characteristic described inconnection with the embodiment is included in some embodiments of theinvention. Thus, the appearances of the phrases such as “in one or moreembodiments,” “in certain embodiments,” “in some embodiments” or “in anembodiment” in various places throughout this specification are notnecessarily referring to the same embodiment of the invention.Furthermore, the particular features, structures, materials, orcharacteristics may be combined in any suitable manner in one or moreembodiments.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It will be apparent to those skilled in the art thatvarious modifications and variations can be made to the method andapparatus of the present invention without departing from the spirit andscope of the invention. Thus, it is intended that the present inventioninclude modifications and variations that are within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A processing chamber comprising: a pedestalpositioned within the processing chamber and comprising a heater, thepedestal configured to hold a substrate; an inlet configured to inputone or more process gases to the processing chamber; and a controlsystem coupled to the processing chamber, the control system comprising:a first configuration to heat the substrate to a first temperature, asecond configuration to expose the substrate to one or more of a plasmafrom a plasma source or radicals from a radical source, a thirdconfiguration to control a flow of an activating agent to the substrateto form hydroxyl terminations thereon, and a fourth configuration toexpose the substrate to multiple cycles of exposure to a SAM molecule,heating the substrate and exposure to the activating agent.
 2. Theprocessing chamber of claim 1, wherein the activating agent compriseswater vapor provided by a remote plasma source.
 3. The processingchamber of claim 1, wherein the pedestal comprises an electrostaticchuck and cooling/heating base.
 4. The processing chamber of claim 3,wherein the electrostatic chuck comprises an Al₂O₃, Y₂O₃ or a ceramicmaterial.
 5. The processing chamber of claim 3, wherein the pedestalfurther comprises a DC electrode and the processing chamber furthercomprising a DC power supply connected to the DC electrode.
 6. Theprocessing chamber of claim 1, further comprising a plasma sourcecomprising a showerhead, wherein the plasma source is coupled to theprocessing chamber.
 7. The processing chamber of claim 6, wherein theplasma source is coupled to an RF power source and the pedestal iscoupled to a first plasma bias power.
 8. The processing chamber of claim7, wherein the pedestal is coupled to a second plasma bias power.
 9. Theprocessing chamber of claim 1, wherein the control system comprises oneor more of a processor, a temperature controller coupled to theprocessor, a memory coupled to the processor, and/or input/outputdevices coupled to the processor.
 10. The processing chamber of claim 9,wherein the memory comprises one or more of transitory memory ornon-transitory memory.
 11. A system comprising: a central transferstation comprising a robot configured to move a substrate betweenchambers connected to the central transfer station; a pre-cleaningchamber connected to the central transfer station, the pre-cleaningchamber comprising one or more of a heater, and one or more of a radicalsource or a plasma source, the pre-cleaning chamber in fluidcommunication with an activating agent; and a control system coupled tothe central transfer station and the pre-cleaning chamber, the controlsystem comprising a first configuration to control heating a substrateto a first temperature, a second configuration to control cleaningcontaminants from the substrate, a third configuration to controlactivating a first surface of the substrate to promote formation of aself-assembled monolayer (SAM) on the first surface by exposing thesubstrate to an activating agent that generates hydroxyl terminations onthe first surface, and a fourth configuration to control movement of thesubstrate from the central transfer station to and from the pre-cleaningchamber using the robot.
 12. The system of claim 11, wherein the firsttemperature is in a range of about 200° C. to about 350° C.
 13. Thesystem of claim 11, wherein cleaning contaminants from the substratecomprises exposing the substrate to one or more of plasma or radicals.14. The system of claim 11, wherein the activating agent comprises watervapor.
 15. The system of claim 12, wherein water vapor is provided by aremote plasma source.
 16. The system of claim 11, further comprising: aSAM deposition chamber connected to the central transfer station, theSAM deposition chamber in fluid communication with one or more reactivegas sources to provide one or more flows of reactive gases comprising aSAM molecule to the SAM deposition chamber, and wherein the controlsystem is coupled to the SAM deposition chamber and further comprises aconfiguration to control formation of a SAM.
 17. The system of claim 14,wherein forming the SAM comprises a plurality of cycles of a SAMformation process followed by a final exposure to a SAM molecule, eachcycle of the SAM formation process comprising exposing the substrate tothe SAM molecule at a second temperature followed by heating thesubstrate to the first temperature and reactivation of the firstsurface.
 18. The system of claim 17, wherein the SAM molecule comprisesan amino-substituted silane with a non-polar tail.
 19. The system ofclaim 16, further comprising: a deposition chamber connected to thecentral transfer station, and wherein the control system is coupled tothe deposition chamber and further comprises a configuration toselectively deposit a film on the substrate.
 20. A non-transitorycomputer readable medium comprising instructions, that when executed bya control system of a processing chamber, cause the processing chamberto perform operations of: heating a substrate to a first temperature;cleaning contaminants from the substrate; generating hydroxylterminations on a first surface of the substrate; and exposing thesubstrate to a SAM molecule at a second temperature.